146 Annals of the Carnegie Museum. 



tabulata, seems to be confined to this stratum, but it is generally abundant 

 and has been found at every locality at which the writer has seen the 

 Brush Creek. In this connection it is interesting to note that the original 

 specimens of this species came from this formation at Bens Creek. As 

 will be seen in the table giving the range of the species, there are several 

 other shells which have so far been found only at this horizon, but they 

 are mostly rare forms, and so are not particularly useful in identifying the 

 horizon. Mention may be made of Bucanopsis marcouana, which is quite 

 common, but this shell is probably not confined to this horizon. Cyrto- 

 ceras cnrtum seems to be restricted to this layer, and though not common, 

 it has been found at a number of localities. The great abundance of 

 Bellerophon percantiatus, Bucanopsis marcouana. PateUosthim montforti- 

 anum, Euphemiis carbonariiis, Eiiomphalus catilloides, Astartella vera, 

 and the presence of Worthenia tabulata are the characteristics which usually 

 serve to identify this formation. It will be noted that the smooth-shelled 

 nautiloid of this stratum is a Solenocheiliis, while the similar shell in the 

 Vanport is an Endobolus. and the robust SphcBrodomcB take the place of 

 the fusiform Solenisci of the lower formation. Marginifera wabashensis, 

 Choneies granulifer, and AmbocoeUa planoconvexa, three species which are 

 very common at higher horizons, make their first appearance here. Alto- 

 gether there is a very great change of fauna between the Vanport and the 

 Brush Creek. 



Dr. Martin evidently found this same fauna in the Brush Creek of 

 Maryland, as is shown by the list of the fossils obtained by him at a 

 locality one mile north of Selbysport, Garrett County. This list, which is 

 published on page 280 of Vol. II of the West Virginia Geological Survey, 

 contains the characteristic species, Worthenia tabulata, and several of the 

 other species which are common in the Brush Creek in Pennsylvania. The 

 only unexpected species is Chonetes mesolobus, wh'ch we have not yet 

 found above the V^anport in this State. 



Pine Creek Limestone. 



From 60 to 90 feet above the Brush Creek is another fossiliferous layer 

 of somewhat wide distribution While fossils are often abundant in the 

 Pine Creek, the writer has so far found only a few localities where good 

 specimens can be obtained, the best collecting places being at Wittmer, 

 Powers Run, Woods Run, and Stoops Ferry, all within a few miles of 

 Pittsburgh. 



While there are a few species which appear to be restricted to this 



